diff options
Diffstat (limited to 'newlib/libc/machine/hppa/strcpy.S')
| -rw-r--r-- | newlib/libc/machine/hppa/strcpy.S | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/newlib/libc/machine/hppa/strcpy.S b/newlib/libc/machine/hppa/strcpy.S new file mode 100644 index 0000000..3068cd5 --- /dev/null +++ b/newlib/libc/machine/hppa/strcpy.S @@ -0,0 +1,285 @@ +/* + * (c) Copyright 1986 HEWLETT-PACKARD COMPANY + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of Hewlett-Packard Company not be + * used in advertising or publicity pertaining to distribution + * of the software without specific, written prior permission. + * Hewlett-Packard Company makes no representations about the + * suitability of this software for any purpose. + */ + +/* + A faster strcpy. + + by + + Jerry Huck (aligned case) + Daryl Odnert (equal-alignment case) + Edgar Circenis (non-aligned case) +*/ +/* + * strcpy(s1, s2) + * + * Copy string s2 to s1. s1 must be large enough. + * return s1 + */ + +#include "DEFS.h" + +#define d_addr r26 +#define s_addr r25 +#define tmp6 r24 +#define tmp1 r19 +#define evenside r19 +#define tmp2 r20 +#define oddside r20 +#define tmp3 r21 +#define tmp4 r22 +#define tmp5 arg3 +#define save r1 + + +ENTRY(strcpy) +/* Do some quick alignment checking on and fast path both word aligned */ + extru,<> s_addr,31,2,tmp6 /*Is source word aligned? */ + ldwm 4(0,s_addr),oddside /*Assume yes and guess that it + is double-word aligned. */ + dep,= d_addr,29,2,tmp6 /*Is target word aligned? */ + b case_analysis + copy d_addr,ret0 +/* Both are aligned. First source word already loaded assuming that + source was oddword aligned. Fall through (therefore fastest) code + shuffles the registers to join the main loop */ +bothaligned: + bb,>= s_addr,29,twoatatime /*Branch if source was odd aligned*/ + uxor,nbz oddside,r0,save + +/* Even aligned source. save holds that operand. + Do one iteration of the main copy loop juggling the registers to avoid + one copy. */ + b,n nullfound + ldwm 4(s_addr),oddside + stwm save,4(d_addr) + uxor,nbz oddside,r0,save + b,n nullfound + ldwm 4(s_addr),evenside + stwm oddside,4(d_addr) + uxor,nbz evenside,r0,save + b,n nullfound + ldwm 4(s_addr),oddside + +/* Main loop body. Entry expects evenside still to be stored, oddside + just loaded. */ +loop: + stwm evenside,4(d_addr) + uxor,nbz oddside,r0,save + +/* mid loop entry */ +twoatatime: + b,n nullfound + ldwm 4(s_addr),evenside + stwm oddside,4(d_addr) + uxor,sbz evenside,r0,save + b loop + ldwm 4(s_addr),oddside + +/* fall through when null found in evenside. oddside actually loaded */ +nullfound: /* adjust d_addr and store final word */ + + extru,<> save,7,8,r0 /* pick up leftmost byte */ + addib,tr,n 1,d_addr,store_final + extru,<> save,15,8,r0 + addib,tr,n 2,d_addr,store_final + extru,<> save,23,8,r0 + addib,tr 3,d_addr,store_final2 + bv 0(rp) + stw save,0(d_addr) + +store_final: + bv 0(rp) +store_final2: + stbys,e save,0(d_addr) /* delay slot */ + +case_analysis: + + blr tmp6,r0 + nop + + /* NOTE: the delay slots for the non-aligned cases load a */ + /* shift quantity which is TGT-SRC into tmp3. */ + /* Note also, the case for both strings being word aligned */ + /* is already checked before the BLR is executed, so that */ + /* case can never occur. */ + + /* TGT SRC */ + nop /* 00 00 can't happen */ + nop + b neg_aligned_copy /* 00 01 */ + ldi -1,tmp3 /* load shift quantity. delay slot */ + b neg_aligned_copy /* 00 10 */ + ldi -2,tmp3 /* load shift quantity. delay slot */ + b neg_aligned_copy /* 00 11 */ + ldi -3,tmp3 /* load shift quantity. delay slot */ + b pos_aligned_copy0 /* 01 00 */ + ldi 1,tmp3 /* load shift quantity. delay slot */ + b equal_alignment_1 /* 01 01 */ + ldbs,ma 1(s_addr),tmp1 + b neg_aligned_copy /* 01 10 */ + ldi -1,tmp3 /* load shift quantity. delay slot */ + b neg_aligned_copy /* 01 11 */ + ldi -2,tmp3 /* load shift quantity. delay slot */ + b pos_aligned_copy0 /* 10 00 */ + ldi 2,tmp3 /* load shift quantity. delay slot */ + b pos_aligned_copy /* 10 01 */ + ldi 1,tmp3 /* load shift quantity. delay slot */ + b equal_alignment_2 /* 10 10 */ + ldhs,ma 2(s_addr),tmp1 + b neg_aligned_copy /* 10 11 */ + ldi -1,tmp3 /* load shift quantity. delay slot */ + b pos_aligned_copy0 /* 11 00 */ + ldi 3,tmp3 /* load shift quantity. delay slot */ + b pos_aligned_copy /* 11 01 */ + ldi 2,tmp3 /* load shift quantity. delay slot */ + b pos_aligned_copy /* 11 10 */ + ldi 1,tmp3 /* load shift quantity. delay slot */ + ldbs,ma 1(s_addr),tmp1 /* 11 11 */ + comiclr,<> r0,tmp1,r0 + bv 0(rp) /* return if 1st byte was null */ + stbs,ma tmp1,1(d_addr) /* store a byte to dst string */ + b bothaligned /* can now goto word_aligned */ + ldwm 4(s_addr),oddside /* load next word of source */ + +equal_alignment_1: + comiclr,<> r0,tmp1,r0 /* nullify next if tmp1 <> 0 */ + bv 0(rp) /* return if null byte found */ + stbs,ma tmp1,1(d_addr) /* store a byte to dst string */ + ldhs,ma 2(s_addr),tmp1 /* load next halfword */ +equal_alignment_2: + extru,<> tmp1,23,8,tmp6 /* look at left byte of halfword */ + bv 0(rp) /* return if 1st byte was null */ + stbs,ma tmp6,1(d_addr) + extru,<> tmp1,31,8,r0 + bv 0(rp) /* return if 2nd byte was null */ + stbs,ma tmp1,1(d_addr) + b bothaligned + ldwm 4(s_addr),oddside /* load next word */ + +/* source and destination are not aligned, so we do it the hard way. */ + +/* target alignment is greater than source alignment */ +pos_aligned_copy0: + addi -4,s_addr,s_addr +pos_aligned_copy: + extru d_addr,31,2,tmp6 /* Extract low 2 bits of the dest addr */ + extru s_addr,31,2,tmp1 /* Extract low 2 bits of the src addr */ + dep r0,31,2,s_addr /* Compute word address of the source. */ + sh3add tmp3,r0,tmp4 /* compute shift amt */ + ldwm 4(0,s_addr),tmp2 /* get 1st source word */ + sh3add tmp1,r0,save /* setup mask shift amount */ + mtctl save,r11 /* set-up cr11 for mask */ + zvdepi -2,32,save /* create mask */ + or save,tmp2,tmp2 /* mask unused bytes in src */ + ldi -1,tmp1 /* load tmp1 with 0xffffffff */ + mtctl tmp4,r11 /* shift count -> shift count reg */ + vshd tmp1,tmp2,tmp3 /* position data ! */ + uxor,nbz tmp3,r0,save + b,n first_null + uxor,nbz tmp2,r0,save + b nullfound1 + mtctl tmp4,r11 /* re-load shift cnt (delay slot) */ + b loop_entry + ldwm 4(0,s_addr),tmp1 /* get next word. delay slot */ + +neg_aligned_copy: + extru d_addr,31,2,tmp6 /* Extract low 2 bits of the dest addr */ + extru s_addr,31,2,tmp2 /* Extract low 2 bits of the src addr */ + dep r0,31,2,s_addr /* Compute word address of the source. */ + sh3add tmp3,r0,tmp4 /* compute shift amt */ + ldwm 4(0,s_addr),tmp1 /* load first word from source. */ +/* check to see if next word can be read safely */ + sh3add tmp2,r0,save + mtctl save,r11 /* shift count -> shift count reg */ + zvdepi -2,32,save + or save, tmp1, tmp1 + uxor,nbz tmp1,r0,save /* any nulls in first word? */ + b first_null0 + mtctl tmp4,r11 + ldwm 4(0,s_addr),tmp2 /* load second word from source */ + combt,= tmp6,r0,chunk1 /* don't mask if whole word valid */ + vshd tmp1,tmp2,tmp3 /* position data ! */ + sh3add tmp6,r0,save /* setup r1 */ + mtctl save,r11 /* set-up cr11 for mask */ + zvdepi -2,32,save + or save, tmp3, tmp3 + uxor,nbz tmp3,r0,save + b,n first_null + uxor,nbz tmp2,r0,save + b nullfound1 + mtctl tmp4,r11 /* re-load shift cnt (delay slot) */ + b loop_entry + ldwm 4(0,s_addr),tmp1 /* get next word. delay slot */ + +chunk1: + uxor,nbz tmp2,r0,save + b nullfound0 + vshd tmp1,tmp2,tmp3 +did_mask: + ldwm 4(0,s_addr),tmp1 /* get next word ! */ +loop_entry: + stbys,b,m tmp3,4(0,d_addr) /* store ! */ + + uxor,nbz tmp1, r0, save + b nullfound2 + vshd tmp2,tmp1,tmp3 /* position data ! */ + ldwm 4(s_addr),tmp2 + stwm tmp3,4(d_addr) + uxor,sbz tmp2,r0,save + b did_mask +nullfound0: + vshd tmp1,tmp2,tmp3 /* delay slot */ + uxor,nbz tmp3,r0,save + b,n nullfound +nullfound1: + stbys,b,m tmp3,4(0,d_addr) + b nullfound + vshd tmp2,r0,save /* delay slot */ + +nullfound2: + uxor,nbz tmp3,r0,save + b,n nullfound + stwm tmp3,4(d_addr) + b nullfound + /* notice that delay slot is in next routine */ + +first_null0: /* null found in first word of non-aligned (wrt d_addr) */ + vshd tmp1,r0,save /* delay slot */ + combt,= tmp6,r0,check4 + extru save,7,8,tmp4 +first_null: + addibt,= -1,tmp6,check3 /* check last 3 bytes of word */ + extru save,15,8,tmp4 + addibt,=,n -1,tmp6,check2 /* check last 2 bytes */ + bv 0(rp) /* null in last byte--store and exit */ + stbys,b save, 0(d_addr) + +check4: + combt,= tmp4,r0,done + stbs,ma tmp4,1(d_addr) + extru,<> save,15,8,tmp4 +check3: + combt,= tmp4,r0,done + stbs,ma tmp4,1(d_addr) +check2: + extru,<> save,23,8,tmp4 + bv 0(rp) + stbs,ma tmp4,1(d_addr) + bv 0(rp) + stbs r0,0(d_addr) + +done: +EXIT(strcpy) |